Lim and co-workers reported that the activation of the 5-HT2BR boosted Ras-phosphoinositide 3-kinases-RAC-alpha serine/threonine-protein kinase (Ras–PI3K/Akt) signaling pathway improved glutamate receptor 1(GluA1)-mediated synaptic plasticity, and showed beneficial effects on the learning ability of FXS mice model [81]. Here, AKT1 is linked to fragile X syndrome.